Developmental and Psychometric Properties of a Belief-based Reproductive Health Behavior Questionnaire for Female Adolescents.

Background
The aim of this study was to develop and evaluate the psychometric properties of a questionnaire for the measurement of reproductive health among female adolescents in Iran.


Methods
This cross-sectional study was conducted among 289 female students aged 12-15 yr in Tehran, Iran from 2015-2016. The participants were selected using multi-stage random cluster sampling. In addition, the Belief-Based Reproductive Health Questionnaire (BBRHQ) was designed using the properties of the Theory of Planned Behavior (TPB).


Results
Exploratory factor analysis of 104 items identified a six-factor solution. These factors jointly accounted for 67% of the observed variance of outcome variable. The confirmatory factor analysis indicated a good fit to the data. In addition, the Cronbach's alpha coefficient showed an excellent internal consistency (alpha=0.92).


Conclusion
Belief-Based Reproductive Health Questionnaire (BBRHQ) is a valid and reliable instrument for measurement of reproductive health behaviors of adolescents.


Introduction
Reproductive health is "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity in all matters relating to the reproductive system and to its functions and processes" (1). Since more than half of the young people in the world start up their sexual activity during their adolescence years, therefore, reproductive health of youth is an important issue which requires a lot of attention (2)(3)(4).
In addition, girls compared to boys suffer from poor knowledge and information on sexual and reproductive health (5). Hence, it is high time to invest in adolescent's reproductive health. Furthermore, a suitable place to reach this goal can be the school setting as it provides easier access to many young people as well as their parents (6). The theoretical underpinning of this research is the theory of planned behavior (TPB) in order to (7). In line with this, several potential distal variables such as socio-demographic variables (8) including age, and locus of control (9), and parental supervision (10) have been proposed which may influence the behavior (11). Perceived parental control may improve children's behaviors (12).
There are a few studies (13) assessing the direct measures of TPB so as to predict reproductive health and behaviors of adolescents (14). Therefore, valid and reliable instruments are needed to assess sexual and reproductive health of adolescents based on behavior change theories of social and behavioral sciences. In the current study, we investigated the influence of perceived parental control within the TPB.

Design and sampling
This cross-sectional study was conducted among 289 female students aged 12 -15 yr in Tehran, Iran from 2015-2016. The adolescents were recruited from 6 female schools in three districts in Tehran, Iran. The schools were selected from among 26 female middle schools in three districts of Tehran (districts 2, 4 and 10), which comprise a mixture of working-class and lower-middle-class families in one of Tehran's most populated inner-city areas. From each school, three classes were selected randomly; one class from each grade. Therefore, 18 classes were enrolled in this study.

Survey Instruments
A self-administered questionnaire was developed using direct measures of TPB theory (15). Some parts of this instrument were based on the questionnaire developed by the WHO (16). Other sections of our instrument were developed based on the literature review and a qualitative study (eight focus-group discussions with 40 participants). The final questionnaire consisted of 145 questions and items.

Socio-economic and demographic characteristics
Thirteen items were included in the questionnaire to elicit personal information on age, place of residence, etc.

Reproductive Health Knowledge
Here, 28 items were used and each was scored using 3 categories (true, false, and do not know). Each correct answer was given score one, and wrong and "do not know" responses were scored zero.

TPB constructs 1.3 Attitude towards reproductive health behavior
Twenty-one items regarding attitude towards reproductive health, derived from relevant literature, were employed.

Subjective norms of reproductive health behavior
Nineteen items were used to assess the influence of important people (parents …) on their opinion about reproductive health.

Perceived Behavioral Control (PBC) of reproductive health behavior
Twenty-five items were used to measure the students' perceptions of behavioral control about behaving in a way that preserves their reproductive health. Answers were rated on a 5-point Likert differential scale ranging from 1 (very difficult) to 5 (very easy). PBC questions were designed (7, 17).

Perceived parental control over reproductive health behavior
Eight items were used to assess this aspect of the study (18).

Behavioral intention to reproductive health behavior
Eighteen items about attitude towards reproductive health, derived from relevant literature, were employed to measure this item.

Face Validity
Ten adolescent girls aged 12-15 were recruited using convenience sampling to determine the ambiguity, relevance, and difficulty of each item. At this stage, none of the items was removed, but 3 items were changed as a result of the adolescents' suggestions.

Content Validity
First, 10 specialists in health education and health promotion, public health, and reproductive health areas reviewed the questionnaire to check its grammar, wording, item allocation, and scaling. In order to calculate the CVR, 13 other specialists were asked to assess each item on a 3point Likert scale (1= were essential, 2= were useful but not essential, 3= were not essential) during the quantitative stage. Then, based on Lawshe's table (19), items that scored greater than or equal to 0.54 were kept on the scale. Throughout this phase, 27 items were removed. In order to calculate the CVI, 10 additional expert panelists were asked to determine the relevance, clarity, and simplicity of each item using a 4-point Likert scale. In addition, two separate groups of experts were used for more precision. However, in accordance with Waltz and Baussel (20), items with CVI value greater than or equal to 0.79 were accepted, and 17 items that did not meet this criterion were deleted. 104 items had a CVI value of greater than or equal to 0.79.

Construct Validity
This validity was investigated using exploratory factor analysis with varimax rotation. The Kaiser-Meyer-Olkin (KMO) and Bartlett's Test of Sphericity were used to assess the appropriateness of the sample for the factor analysis. Eigenvalues above 1 and scree plot were used to determine the number of factors. Factor loadings equal to or greater than 0.3 were considered appropriate (21). Data were analyzed using SPSS version 23.0 (Chicago, IL, USA) as well as AMOS 23.

Reliability
Internal consistency was evaluated by Cronbach's α coefficient (22). A sub-sample of students (n=45) completed the questionnaire twice with a 2-wk interval in order to examine the stability of the scale by calculating Intra-class Correlation Coefficient (ICC) where the ICC of 0.4 or above was considered acceptable(23) ( Table 1).

Ethical approval
The

Results
The socioeconomic and demographic characteristics of the studied participants are shown in Table 2.

Validity
In the qualitative face validity, participants stated that they have had no problems in reading and understanding the items. In the quantitative con-tent validity phase, items with CVR and CVI less than 0.62 and 0.80 were respectively omitted (24 items). The mean of content validity ratio was 0.64. Moreover, the mean of the content validity index (CVI) was 0.74. Exploratory factor analysis (EFA) was used to evaluate construct validity (Table 3).
CFA results confirmed the exploratory six-factor structure (RMSEA, χ2/df, TLI, IFI, NFI, CFI, AGFI, GFI and SRMR) ( Table 4). Flexibility and ability to communicate effectively with others is easy for me during adolescence. Most people who are important to me think that the changes during puberty such as physical and emotional changes prevent me from carrying out social activities such as attending social meetings.

Discussion
This study was prospected to develop and validate an instrument for assessing the adolescents' reproductive health and behaviors. In this study, the constructs of the modified theory of TPB were evaluated using the direct method (24). EFA was conducted for TBP structures and it led to removal of 10 items from the original questionnaire. The final form with 104 items was classified into six subscales. Having both exploratory and factor analyses applied, the results indicated a good structure for this new instrument. Exploratory factor analysis indicated that the six-factor structure of the questionnaire could jointly account for 67% of the cumulative observed variance. Moreover, according to the results of CFA, the questionnaire with 4 given domains is a good instrument for measuring the reproductive health among adolescents in Iran.
In this study, a ratio of 0.64 was calculated for the content validity and the mean of the content validity index (CVI= 0.74) was likewise calculated. The mean of the CVR and CVI was reasonable and satisfactory. However, they obtained low values in some questions rooted in differences in the cultural context of the countries, so they have amended again in writing. Results of the internal consistency suggest that the provided questionnaire had acceptable reliability. The study revealed an internal consistency of 0.85 to 0.91 for TPB (25). In addition, an internal consistency of 0.86 was reported for the constructs of the TPB (26). Moreover, internal consistency of the final scale indicates a desirable reliability. In addition, ICC showed appropriate stability for the scale as it was examined by 45 participants with a 2-week interval (0.92) (15). This instrument had a number of strengths. Adding item 28 to the instrument was one of them. Another important feature of our questionnaire lies in the way it was worked out; in spite of other questionnaires with short statements, we used long and complete sentences. The main feature of the BBRHQ was the fact that it was developed for middle age students and contained items on nutrition and exercise, adolescents' health, menstrual health, and AIDS. Notably, a previous study among adolescent boys aged 15-18 yr assessed their sexual and reproductive health knowledge, attitude, and behaviors in Tehran (13). The advantages of the current study over the previous instrument were that the current instrument covers other aspects of reproductive health such as nutrition, exercise, puberty, menstrual hygiene, and AIDS. Its psychometric aspects have also been evaluated while other previous instruments lack this point.

Conclusion
The BBRHQ is a valid and reliable instrument for evaluating the reproductive health, attitude, and behavior among female adolescents in Iran.

Ethical considerations
Ethical issues (Including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, redundancy, etc.) have been completely observed by the authors.